In recent years, light scanning optical systems have come into use which transmit a light beam generated by a light source device through an optical fiber, and which collect light from an object using a lens by scanning the area where the light is imaged so as to obtain image information of the object. In U.S. Pat. No. 5,120,953, a small scanning optical device is disclosed for observing, with magnification, living tissues. Light from an object is imaged and this light is then collected by scanning an end of an optical fiber at an image surface using an actuator. Collection of light from an object by scanning with scanning mirrors is also disclosed.
However, in a method of scanning that uses an end of an optical fiber as a light source, the design and manufacture of a condensing optical system having a high resolution and wide field of view for such a light source become difficult, since rays of light emitted in different directions from the light source at each scanning position need to be collected. Also, where the object to be observed has a low reflectivity, as is the case where the object to be viewed is living tissue, it is necessary to reduce stray light that is generated inside the optical system in order to increase the signal-to-noise ratio (hereinafter S/N ratio) so as to produce a satisfactory image of the object.
The object of the present invention is to provide an optical device that enables high resolution and a wide field of view to be obtained using a light scanning optical device that is compact. In addition, it is desirable to provide a light scanning optical device which reduces stray light generated inside the optical system so as to provide a high S/N ratio in the image of the object.